Chemical Element Facts

Chemical Element Facts A chemical element is a form of matter that cant be broken into smaller pieces by any chemical reaction. Essentially, this means elements are like different building blocks used to construct matter.   At present, every element in the  periodic table  has been discovered or created  in a lab. There are 118 known elements. If another element, with a higher atomic number (more protons) is discovered, another row will need to be added to the periodic table. Elements and Atoms A sample of a pure element consists of one type of atom, which means each atom contains the same number of protons as every other atom in the specimen. The number of electrons in each atom can vary (different ions), as can the number of neutrons (different isotopes). Two samples of the exact same element may look completely different and exhibit different chemical and physical properties. This is because the atoms of the element can bond and stack in multiple ways, forming what are called allotropes of an element. Two examples of allotropes of carbon are diamond and graphite. The Heaviest Element The heaviest element, in terms of mass per atom, is element 118. However, the heaviest element in terms of density is either osmium (theoretically  22.61 g/cm3) or iridium (theoretically  22.65 g/cm3). Under experimental conditions, osmium is almost always more dense than iridium, but the values are so close and dependent on so many factors, it really makes no difference. Both osmium and iridium are about two times heavier than lead! The Most Abundant Elements The most abundant element in the universe is hydrogen, accounting for about 3/4 of the ordinary matter scientists have observed. The most abundant element in the human body is oxygen, in terms of mass, or hydrogen, in terms of atoms of an element present in the highest quantity. The Most Electronegative Element Fluorine is best at attracting an electron to form a chemical bond, so it readily forms compounds and participates in chemical reactions. This makes it the most electronegative element.  At the opposite end of the scale is the most electropositive element, which is the one with the lowest electronegativity. This is the element francium, which does not attract bonding electrons. Like fluorine, the element is extremely reactive, too, because compounds most readily form between atoms that have different electronegativity values. The Most Expensive Elements Its difficult to name the most expensive element because any of the elements from francium and higher atomic number (the transuranium elements) decay so quickly they cant be collected to be sold. These elements are unimaginably expensive because they are produced in a nuclear laboratory or reactor. The most expensive natural element you could actually buy would probably be lutetium, which would run  around $10,000 for 100 grams. Conductive and Radioactive Elements Conductive elements transfer heat and electricity. Most metals are excellent conductors, however, the most conductive metals are silver, followed by copper and gold. Radioactive elements  release energy and particles via radioactive decay. Its hard to say which element is the most radioactive, as all elements higher than atomic number 84 are unstable. The highest measured radioactivity comes from the element polonium. Just one milligram of polonium emits as many alpha particles as 5 grams of radium, another highly radioactive element. Metallic Elements The most metallic element is the one which displays traits of metals to the highest extent. These include the ability to be reduced in a chemical reaction, the capacity to form chlorides and oxides, and the ability to displace hydrogen from dilute acids. Francium is technically the most metallic element, but since there are only a few atoms of it on Earth at any given time, cesium deserves the title.

French Noun Endings Can Be a Telltale Sign of Gender

French Noun Endings Can Be a Telltale Sign of Gender French gender  is a headache for many students of French. Why is manteau masculine and montre feminine? Why is  tà ©moin  always masculine and  victime  always feminine? As vexing as this subject is for nonnative speakers, we simply have to accept that French gender is here to stay. In fact, consider yourself lucky that youre studying French; in German and Latin, for instance, youd have to learn three genders (masculine, feminine and neuter), and in still other languages, it gets even more complicated. It might help to know that grammatical  gender (what were discussing here) has nothing to do with natural gender, which is actual, physical gender of living beings. Linguist Andrew Livingston tells us grammatical gender is a way of classing nouns thats older than recorded history. Its deeply embedded in the DNA of an array of Indo-European languages that trace their lineage to a common ancestor, which probably needed to differentiate between the animate and the inanimate. In French, theres simply no way to know the gender of every single noun other than by memorizing the gender of each. There are, however, certain patterns in suffixes and word endings that are a tip-off. As you can see by the number of exceptions here, these gender patterns are not foolproof indicators, but they can help. Before we begin, a couple of notes: We try to list the most common and, thus, most useful exceptions; we avoid obscure exceptions. Also, to avoid confusion, we do not list  dual-gender nouns.   French Masculine Nouns Here are some suffixes that usually indicate masculine nouns, as well as some important exceptions. -ageExceptions: la cage, une image, la nage, la page, la plage, la rage -b -bleExceptions: une cible, une à ©table, une fable, une table -cException: la fac (apocope of la facultà ©) -cleException: une boucle -d -deExceptions: la bride, la merde, la mà ©thode, la pinà ¨de; -ade, -nde, -ude endings -à ©Exceptions: la clà ©, la psychà ©; sà ©, tà ©, and tià © endings -eauExceptions: leau, la peau -à ¨geException: la Norvà ¨ge -et -eurNote:  This applies mainly to names of professions and mechanical or scientific things; also see -eur in the list of feminine endings. -fExceptions: la soif, la clef, la nef -iExceptions: la foi, la fourmi, la loi, la paroi -ing -isme -k -lException: une roseval -mException: la faim -meExceptions: une alarme, une à ¢me, une arme, la cime, la coutume, la crà ¨me, là ©cume, une à ©nigme, une estime, une ferme, une firme, une forme, une larme, une plume, une rame, une rime, -mme ending -mentException: une jument -nExceptions: la faà §on, la fin, la leà §on, la main, la maman, la ranà §on; -son and -ion endings -oExceptions: la dactylo, la dynamo, la libido, la mà ©tà ©o, la moto, la steno (most of these are apocopes of longer feminine words) -oir -one -ou -p -rExceptions: la chair, la cour, la cuiller, la mer, la tour (see feminine -eur) -sExceptions: la brebis, la fois, une oasis, la souris, la vis -steExceptions: la liste, la modiste, la piste; names for people like un(e) artiste, un(e) nudiste, etc. -tExceptions: la burlat, la dent, la dot, la forà ªt, la jument, la mort, la nuit, la part, la plupart, la ziggourat -treExceptions: la fenà ªtre, une huà ®tre, la lettre, la montre, la rencontre, la vitre -uExceptions: leau, la peau, la tribu, la vertu -xExceptions: la croix, la noix, la paix, la toux, la voix Feminine Noun Endings Here are some suffixes that usually indicate feminine nouns, as well as some important exceptions. Remember, we list here the most common endings, because these will be the most useful for you to know. -aceExceptions: un ace, un palace -adeExceptions: le grade, le jade, le stade -aleExceptions: un chà ¢le, un pà ©tale, un scandale -ance -beExceptions: un cube, un globe, un microbe, un tube, un verbe -ceExceptions: un artifice, un armistice, un appendice, le bà ©nà ©fice, le caprice, le commerce, le dentifrice, le divorce, un exercice, un office, un orifice, un prà ©cipice, un prince, un sacrifice, un service, le silence, le solstice, le supplice, un vice -cà ©Exception: un crustacà © -eNote:  Most countries and names that end in e are feminine. -eeException: un pedigree -à ©eExceptions: un apogà ©e, un lycà ©e, un musà ©e, un pà ©rigà ©e, un trophà ©e -esse -eurNote: This applies mainly to abstract qualities and emotions, except le bonheur, lextà ©rieur, lhonneur, lintà ©rieur, le malheur, le meilleur. Also see -eur  on the list of masculine endings. -feException: le golfe -ieExceptions: un incendie, le foie, le gà ©nie, le parapluie, le sosie -ià ¨reExceptions: larrià ¨re, le cimetià ¨re, le derrià ¨re -ineExceptions: le capitaine, le domaine, le moine, le magazine, le patrimoine -ionExceptions: un avion, un bastion, un billion, un camion, un cation, un dominion, un espion, un ion, un lampion, un lion, un million, le morpion, un pion, un scion, un scorpion, un trillion -iqueExceptions: un graphique, un pà ©riphà ©rique -ireExceptions: un auditoire, un commentaire, un dictionnaire, un directoire, un horaire, un itinà ©raire, livoire, un laboratoire, un navire, un pourboire, le purgatoire, le rà ©pertoire, le salaire, le sommaire, le sourire, le territoire, le vocabulaire -ise -iteExceptions: lanthracite, un ermite, le granite, le graphite, le mà ©rite, lopposite, le plà ©biscite, un rite, un satellite, un site, un termite -lleExceptions: le braille, un gorille, un intervalle, un mille, un portefeuille, le vaudeville, le vermicelle, le violoncelle -mmeExceptions: un dilemme, un gramme, un programme -ndeException: le monde -nne -oleExceptions: le contrà ´le, le monopole, le rà ´le, le symbole -rreExceptions: le beurre, le parterre, le tonnerre, le verre -seExceptions: un carosse, un colosse, le gypse, linverse, un malaise, un pamplemousse, un parebrise, le suspense -sà ©Exceptions: un exposà ©, un opposà © -sion -sonExceptions: un blason, un blouson -tà ©Exceptions: un arrà ªtà ©, le comità ©, le comtà ©, le cà ´tà ©, un dà ©putà ©, un à ©tà ©, le pà ¢tà ©, le traità © -tià © -tionException: le bastion -udeExceptions: le coude, un interlude, le prà ©lude -ueException: un abaque -uleExceptions: le prà ©ambule, le scrupule, le tentacule, le testicule, le và ©hicule, le ventricule, le vestibule ï » ¿-ureExceptions: le centaure, le cyanure, le dinosaure, le murmure